Protective surface treatment for metal alloy components during manufacturing and thereafter

Abstract

A protective surface treatment in the form of a coating for steel or another metal or metal alloy capable of providing oxidation resistance in an inert gas furnace or air-containing furnace is provided. The coating is formed by a solution including at least one flux agent, such as boric acid, and at least one binder, such as polyvinylpyrrolidone (PVP), polyvinylpyrrolidone/vinyl acetate (PVP/VA), hydrooxypropylcellulose (HPC), ethylcellulose, and/or acrylics. The solution also includes at least one solvent, such as methanol or ethanol and can include various additives. The finished coating includes iron borate and provides a glassy surface.

1 . A method of manufacturing a component, comprising the steps of:
 applying a mixture to a body portion, the body portion including a metal or metal alloy;   the mixture including a flux agent, at least one binder, and at least one solvent;   the flux agent including at least one of boric acid; sodium borate; sodium tetraborate; disodium tetraborate; boron oxide; calcium fluoride; sodium carbonate; potash; charcoal; coke; lime; lead sulfide; ammonium chloride; limestone; metal halide; zinc chloride; hydrochloric acid; phosphoric acid; hydrobromic acid; salt of a mineral acid; mineral acid with amine; carboxylic acid; fatty acid; amino acid; organohalide; boron; silicon; a mixture containing 20 wt. % MnO, 15 wt. % CaF 2 , and SiO 2  to CaO ratios varying from 5.50 to 1.16; tin(II) chloride; a fluoride; and precursors to silicate and borosilicate glasses; and   heating the mixture on the body portion to a temperature in the range of 200 to 1200° C.   
     
     
         2 . A method according to  claim 1 , wherein the body portion is formed of steel. 
     
     
         3 . A method according to  claim 1 , wherein the flux agent includes at least one of boric acid, sodium borate, borax, sodium tetraborate, and disodium tetraborate; and the heating step includes forming iron borate. 
     
     
         4 . A method according to  claim 1 , wherein the flux agent is present in an amount of 1 to 30 wt. %, based on the total weight of the mixture. 
     
     
         5 . A method according to  claim 1 , wherein the binder includes at least one of polyvinylpyrrolidone (PVP), polyvinylpyrrolidone/vinyl acetate (PVP/VA), hydroxypropyl cellulose (HPC), ethyl cellulose, and acrylic. 
     
     
         6 . A method according to  claim 1 , wherein the binder is present in an amount of 1 to 30 wt. %, based on the total weight of the mixture. 
     
     
         7 . A method according to  claim 1 , wherein the solvent includes at least one of methanol, acetone, MEK, ethanol, and denatured alcohol. 
     
     
         8 . A method according to  claim 1 , wherein the mixture further includes at least one additive, and the at least one additive includes at least one of a solvent soluble element or compound of Zn, Cr, Mn, Si, B, Al, Cu, Co, Ni, Zr, Hf, Ti, Ta, Mo, W, Ag, Au, Fe, TiO 2 , SiO 2 , Al 2 O 3 , and/or SiO 2 —Al 2 O 3 ; nano sized particles of C, B, Si, Al, Zn; and nano sized oxides of Al, Si, Ti, Cr, and Mo. 
     
     
         9 . A method according to  claim 8 , wherein the at least one additive is present in an amount of 0.1 to 1 wt. %, based on the total weight of the mixture. 
     
     
         10 . A method according to  claim 1 , wherein the flux agent is boric acid, the binder is PVP, and the solvent is methanol. 
     
     
         11 . A method according to  claim 1 , wherein the flux agent is boric acid, the binder is acrylic, and the solvent is ethanol. 
     
     
         12 . A method according to  claim 1 , wherein the step of applying the mixture includes at least one of spraying, painting, and rolling the mixture on the body portion. 
     
     
         13 . A method according to  claim 12 , wherein the body portion is provided as a coil formed of steel, and the step of applying the mixture includes rolling. 
     
     
         14 . A method according to  claim 1  including curing the binder by heating the mixture at a temperature in the range of 100 to 300° F. 
     
     
         15 . A method according to  claim 14 , wherein the furnace includes an atmosphere of air, nitrogen, or nitrogen and natural gas. 
     
     
         16 . A method according to  claim 1  including hot forming the body portion after heating the mixture on the body portion to 600 to 1200° C. 
     
     
         17 . A method according to  claim 1  including hot forming the body portion after heating the mixture on the body portion to a temperature of 940° C. 
     
     
         18 . A component, comprising:
 a body portion including a metal or metal alloy,   a coating disposed on said body portion, and said coating including iron borate.   
     
     
         19 . A component according to  claim 18 , wherein said coating includes at least one of Zn, Cr, Mn, Si, B, Al, Cu, Co, Ni, Zr, Hf, Ti, Ta, Mo, W, Ag, Au, Fe, TiO 2 , SiO 2 , Al 2 O 3 , and/or SiO 2 —Al 2 O 3 ; nano sized particles of C, B, Si, Al, Zn; and nano sized oxides of Al, Si, Ti, Cr, and Mo. 
     
     
         20 . A component according to  claim 18 , wherein said body portion is formed of steel. 
     
     
         21 . A component according to  claim 18 , wherein said component is a part for an automotive or truck. 
     
     
         22 . A component according to  claim 18 , wherein said component is a gear, and said coating prevents decarburization during heat treating. 
     
     
         23 . (canceled) 
     
     
         24 . A component, comprising:
 a body portion including a metal or metal alloy,   a coating disposed on said body portion, and said coating including metal oxide, silicate, borosilicate, and/or alkali metal silicate.